Catena Aurea on Matthew 27:39–44: Augustine of Hippo

It may seem that Luke contradicts this, when be describes one of the robbers as reviling Him, and as therefore rebuked by the other. But we may suppose that Matthew, shortly alluding to the circumstance, has used the plural for the singular, as in the Epistle to the Hebrews we have, “Have stopped the mouths of lions,” [Heb. 11:33] when Daniel only is spoken of. And what more common way of speaking than for one to say, See the country people insult me, when it is one only who has done so. If indeed Matthew had said that both the thieves had reviled the Lord, there would be some discrepancy; but when he says merely, “The thieves,” without adding ‘both,’ we must consider it as that common form of speech in which the singular is signified by the plural.